Here's an idea. This might work. Uninstall all the drivers. Then uninstall the card (don't take it out, just uninstall in device manager). Restart. Let it say "New Device Found" and install the first set of drivers that you have like from the CD that came with the card. Restart. If things are working fine till now, install the latest drivers. If that doesn't work, try to switch that card out with a friend and see if the card messes up on his/her computer. And also reinstall the latest non-beta DirectX. Don't use a beta because those aren't fully operational yet and everything should be as stable as possible. Get back to me on this, I hope it works.